Energy efficiency in hydronic heating systems is typically measured in which unit?

The measurement of energy efficiency in hydronic heating systems is commonly expressed in Annual Fuel Utilization Efficiency (AFUE). AFUE indicates how efficiently a heating system converts fuel into usable heat over the course of a year. Specifically, it is a percentage that represents the ratio of the amount of heat produced to the amount of fuel consumed, thus giving a clear perspective on the effectiveness of the heating system.

For hydronic systems, which often rely on boilers for heating water that circulates through a building, AFUE is particularly relevant. It helps assess the performance of the boiler and provides guidance to consumers on the potential energy savings they might expect. A higher AFUE percentage signifies better efficiency, meaning more of the fuel's energy is being converted to heat rather than being wasted.

The other measurement options, while relevant in their respective contexts, do not apply directly to the assessment of hydronic heating systems. The Thermal Efficiency Ratio (TER) relates more to cooling systems, and the Seasonal Energy Efficiency Ratio (SEER) applies to air conditioning systems. Cubic Feet per Minute (CFM) measures airflow, which is important for ventilation but does not provide a direct assessment of heating efficiency.